New esters of 1, 3, 5-estratriene-3, 16, 17-triol and novel pharmaceutical compositions containing new esters of 1, 3, 5-estratriene-3, 16, 17-triol and esters of 1, 3, 5-estratriene-3, 16, 17-triol



United States Patent The present invention relates to new esters of 1,3,5(l0)- estratriene-3,16,17-triol, and novel pharmaceutical compositions with persistent efiicacy which contain as its effective ingredients 1,3,5(l0)-estratriene-3,16,17-triol esters.

To be more specific, this invention relates to anew ester of l,3,5(10)-estratriene-3(fi),l6(a),l7(a)-triol and monobasic saturated fatty acid (2-6 carbon atoms) esters and benzoic acid esters of 1,3,5(lO)-estratriene-3,l6(a),

17 (;8)-triol; and also relates to pharmaceutical compositions which contain as its eifectiveingredient l,3,5(l0)- estratriene-3 (B),16(O5),17(Ot)-tfl0i ester and a monobasic saturated fatty acid (2-6 carbon atoms) esters, or benzoic acid esters, of 1,3,5(lO)-estratriene-3,l6(a),l7(,8)-triol; and are used for treatment of vaginitis, cervicitis, climacteric disturbance, menorrhagia, etc., and for shortening labour and facilitating delivery.

There are several known isomers of 1,'3,5(10)-estratriene-3,l6,l7-triol, depending on the configuration of hydroxyl groups, among them, one, so-called estriol and clinically applied, is 1,3,5 (10)-estratriene-3,16(a),l7(fl)- triol and is just like estradiol a kind of naturally occurring estrogen. However, according to the results of bioassay, its estrogenic activity is only about 1/ 100 comparing with that of estradiol; for this reason estriol has been regarded as amere metabolite of estradiol and one having relatively small efficacy for treatment. Meanwhile, Puck et al. discovered in 1957 that estriol is re? markably inferior to estradiol in the effect of proliferating the endometrium, but superior to it in the effect on the endocer vix and vaginal epitherium; and thereafter the merit of estriol as a means of treatment has been reevaluated.

Estradiol by virtue of its inhibition of the production of gonadotropin in the pituitary gland is highly prized as a powerful means of controlling climacteric disturbance, but its strong function of proliferating the endometrium causes a withdrawal bleeding of the uterus, which has been regretted as the fatal sideefi'ect of estradiol.

By contrast, estriol, even if administered in large doses, will not exert such a strong effect of endometrium proliferation as to cause a uterine bleeding, so that it has the ultimate stage of pregnancy; Puck et al. attributed to this increase an effect of making the pelvis flexible; widening, softening and dilatating the cervix and vagina. Based on this specific action of estriol upon the cervix and vagina, application of estriol to delivery has come to be tried.

3,166,473 Patented Jan. 19, 1965 as derivatives obtained when the above-mentioned estriol is detected or identified, but it has never been applied for clinical purposes.

Estriol, as stated above, has been clinically applied in diiferent'forms; injection for parenteral use, tablets for oral administration, or tablets for vaginal use. To secure full treatment effect, however, it must be repeatedly administered.

The present inventors have sought for manyyears for the method of making the effects of the above-mentioned estriols stronger and more persistent and vfinally discovered that through esterifiication of the hydroxyl groups of estriols by monobasic saturated fatty acids or benzoic acid, the estrogenic action of estriol could be rendered persistent and stronger.

Thus, the objective of the present invention is to offer new esters of 1,3,5 (10)-estratriene-3,l6(a),17(5)-triol and 1,3,5(10)-estratriene-3(fl),16(or),17(a) -triol which can hold an efficacy for a long time by a single administration act with a desired acid.

Meanwhile, 1,3,s 10 estratriene 3(p),16(u.),17 (a)- triol is less strong in its estrogenic action than 1,3,5(10)- estratriene-3,16(a),17( 3)-triol; therefore it has never been adopted for treatment. In the .meantime, 1,3,5(1 0)- estratriene-'3,l6(a),l7(B)-triol triacetate and 1,3,5(l0)- estratriene-3,l6(a),17(,8)-triol 16,17 diacetate are known and tooffer a pharmaceutical composition, usable for treatment of vaginitis, cervicitis, menorrhagia, etc., and for shortening labour and facilitating delivery, that contains as its effective ingredients esters of 1,3,5(10)- estratriene-3,16(a),17(;9)-triol and an ester of 1,3,5 (10)- estratriene-3 (,8) 16(a), 17 (ed-triol.

Three esterifiable hydroxyl groups are contained in 1,3,5(10) estratriene 3,l6(a),l7(fi) triol and 1,3,5- estratriene-3(fl),l6( x),17(u)-trio1. The esters of this invention embraces all types, namely one with only one of these hydroxyl groups esterified, one with two of them esterified, and one with all three of them esterified.

The esters of this invention can be produced by the known process of esterification of the hydroxyl groups.

For instance:

(1) 1,3,5-estratriene-3,16(a),17(fi)-triol or 1,3,5(10)- estratriene-3 (/3),16(u),17(u)-triol is made directly to re- (2) 1,3,5(10)-estratriene-3,l6(a),l7(,B)-trio1 or 1,3,5- estratriene-3(B),16(),17(u)-triol is made to react in an organic solvent like pyridine, dichloroethane, benzene, cyclohexane with a desired acid anhydride.

(3) 1,3,5(10)-estratriene-3,16(a),17( 3)-triol or 1,3,5- estratriene-3(n),16(a.),17(u)-triol is dissolved in an aqueous solution of an alkali metal hydroxide like caustic soda. or caustic potash and made to react with a desired acid halogenide like chloride, bromide, or iodide.

By these processes, adesired ester can be obtained. The acids employed .in the above-mentioned processes or ester production are monobasic saturated fatty acid with 2 to 6 carbon atoms'and benzoic acidyas such fatty acid may be taken acetic acid, propionic acid, butyric acid, Valerie acid and caproic acid.

As actual examples of esters embraced by this invention may be mentioned the'followingz (i) 1,3,5(10)-6Si121t1i6I16-3,16(0c),17(,B)-i1i0l triacetate,

M.P. 126-427 C.; 7 (ii) 1,3,5(10)estratriene-3(B acetate, M.P. 162164 C.; (iii) f1,3,5(10)-estratriene-3,l6(a),17(fl)-triol 16,17-

diacetate, M.P. 193-195 C.; (iv) 1,3,5 (l0)-estratriene-3,l6(a),17(,B)-trio1 tripropionate, M.P. 99101 C.; (v) 1,3,5(l0)-estratriene3,16(a),l7(,B)-triol 16,17

dipropionate, M.P. 127-l30 C.;' (vi) 1,3,5(10)-estratriener3,16(a),17( 8)-triol 16- monopropionate, M.P. 205-207 Ci; 1 i (vii) 1,3,5 l0) -est1'atriene-3,16(a) ,17 (p)'-trio1 tributyrate oil; (viii) 1,3,5(l0)-estratriene-3,16(a),l7(fi) triol tri valerate oil; 4

,16 (a),17(ot)-trio1 tri- (ix) '1,3,5(10)-estratriene-3,16(u),17(fi)-trioltricaproate oil;

meagre 3 (x) 1,3,5(10)-estratriene-3,16(a) ,17(B)-triol tribenzoate,

M.P. 168169 C.; (xi) 1,3,5(10)-..stratriene-3,16(a),17(fi)-triol 3-monobenzoate, M.P. 227228 C.; (xii) 1,3,5(10)-estratriene-3,16(a),17(t3)-triol 3-acetyl- 16,17-dipropionate, M.P. 77-78 C.;

Comparison of the duration of estrogenic action by vaginal smear test between the esters of this invention and 1,3,5(10)-estratriene-3,16(a),l7(fi)-triol is made in Table I.

In this test, the test solutions were made by dissolving the esters of this invention in a mixture of sesame oil 70% and benzyl benzoate 30%, while the control was a solution of 1,3,5 (10)-estratriene-3,16(a),17(,8)-triol in propylene glycol.

For testing, these test solutions and the control were respectively injected into groups of more than 10 ovariectomized mice and the number of days on which more than 60% of these mice exhibited estrus was compared. The quantity of each ester was expressed in terms of estriol equivalent.

TABLE I Comparison of the duration of estrogenic action on vaginal smear test These results show that 1,3,5(10)-estratriene-3,16(a), 17(,B)-triol as esterified by monobasic saturated fatty acid with 2 to 6 carbon atoms or benzoic acid will have the duration of its estrogenic action prolonged; particularly the above-mentioned estriol triesters of acetic acid, propionic acid or butyric acid will have the duration remarkably extended and the said action considerably intensified, which is testified by Table 11.

TABLE II Comparison of estrogenic activities on uterine weight methods Days after injection of samples Samples I Uterine weight (mg) 011 only (control) 12.2 13.3 11.0 14.9 1,3,5(10)-estratriene-3,16(a),17(fi)-tri0l (control 14.3 12.1 11.2 13.1 1,3,5 (10)-OSt1'It!l0HG-3,l6(a) ,17(B)-tril triaeetate 54.5 21.1 17.8 14.5 1,3,5()-estratriene-3,16(a),17(,J)rtriol tripropionate 88.5 77.1 52.2 29.1 1,3,5(10)-estratriene-3,16(a),IKfD-triol tributylate 11. 0 21.1

Meanwhile, it has also been observed that 1,3,5(10)- estratriene-3,16(ot),17(fl)-triol with admittedly very weak estrogenic efiect can have its effect and duration markedly enhanced through esterification over those of 1,3,5 (10)- estratriene-3,16 (a) ,17 (fl)-triol.

Thus, it has been made clear through the test of vaginal smear and uterine weight of ovariectomized mice that the effect and its duration of estriol can be increased through esterification. Next, the clinical effect will be explained.

When 10 mg. of estratriene-3,16(a),17(fi)-triol tripropionate was administered in one dose to an ovariectomized Woman, excretion of estriol in her urine lasted about 7 to 12 days, the maximum amount being excreted on the third day after injection. The vaginal epitherium proliferation, as measured in terms of smear index in vaginal smear test, continued for about 14 days, the maximum value being found between the 4th and the 8th day.

On the other hand, it was observed that only a single injection of 10 mg. of estriol tripropionate 5 to 7 days before full-term could remarkably shorten the stadium of labour.

The above-mentioned reaction and a striking clinical usefulness will never be expected from only a single administration of estriol; this was presumably due to the enhanced eifect and its duration of esterified estriol. Shortening the stadium of labour and facilitating delivery, predicted by Puck et al. from many experimental and clinical observations, was for the first time practically and economically actualized by using esters of the present invention; this was also due to the enhanced softening and relaxing effect of cervical canal, derived from the improved elevation of efficacy and its duration.

Actual examples or" ester production as covered by this invention are given in the following:

EXAMPLE 1 1,3,5 l0) -estratriene-3,16(a) ,17(B)-triol tripropionate. Three grams of 1,3,5(10)-estratriene-3,16(a),17(fl)-triol was dissolved in 60 cc. of pyridine; 30 cc. of propionic anhydride was added to the solution, which was then heated at C. for 6 hours, The mixture was diluted with cc. ofether, successively Washed with n-HCl, 5%-Na CO and water, and then dried over anhydrous sodium sulfate. Then, the ether was evaporated; and the residue was recrystallized several times from ethylalcohol, producing 3.5 g. of 1,3,5(10)-estratriene-3,16(a),17fl)- triol tripropionate with a melting point of 99 to 101 C.

EXAMPLE 2 on the solution while being cooled by ice. The solution was then agitated for six hours at room temperature and left to stand overnight. The separated precipitate was fil- .tered. The obtained substance, after being refined by alumina column chromatography, was recrystallized from methanol, producing 1,3,5(1O)-estratriene-3,16(a),17( 3)- triol 3-monobenzoate with a melting point of 227 to 228 C.

EXAMPLE 4 1,3,5(10)-estratriene-3(fi),l6(a),17(a)-triol triacetate. One gram of l,3,5(10)-estratriene-3(B),l6(a),l7(a)-triol Was dissolved in a mixture of 28 cc. of pyridine and 10 cc. of acetic anhydride, and then heated at 70 C. for six hours. The mixture was diluted with 50 cc. of ether, successively washed with n-HCl, 5%-Na CO and water, and then dried over anhydrous sodium sulfate. Thereupon, the ether was evaporated and then the residue was recrystallized from ethyl alcohol, producing 1.1 g. of-1, 3,5-estratriene-3(,B),16(a),17(a)4triol triacetate with a melting point of 162 to 164? C. was obtained.

EXAMPLE 5 1,3,5 10) -estratriene-3,16(u) ,17 (,8) -triol 16-monopropionate. One gram of 1,3,5(l)estratriene-3, 16(a), 17'(fi)-tri01 was dissolved in 10 cc. of propionic acid and heated at 110 to 120 C. for five hours. After cooling, the reactant was poured into water. The separated precipitate was filtered; the filter cake, after being refined by alumina column chromatography, was recrystallized from methanol, producing 1,3,5 l0)-estratriene-3,16(a),17(fi)- triol l6-monopropionate with a melting point 205 to 207 C.

estratriene 3, 16(u),17 ()-triol 16,-17-dipropionate with a melting point of 12 7 to 130 C. This crystal was dissolved in a mixture of 15 cc. of dry pyridine, and 0.9 g.

of acetic anhydride, and then left to stand at room temperature for 24 hours. The reaction mixture was mixed with 1 cc. of methanol, left to stand for two hours, then evaporated it to a syrup under reduced pressure. The syrup was dissolved in 50cc. of ether, successively washed with n-HCl, 5%-'Na CO and further with water; then dried by addition of anhydrous sodium sulfate. By evapo- Afiter cooling, the reactant was.

rating the solvent'and recrystallizing from methanol,

l,3,5 (10)-estratriene-3,l6-(ot),17(B)-triol 3-acetyl 16,17- dipropionate with a melting point of 77 to 78 C. was obtained.

When the esters. of this invention are to be used for treatment of vaginitis, cervicitis, menorrhagia, climacteric disturbance, etc. and for relief of difliculty in delivery, they can be prepared in appropriate'forms, for instance; solution for injection, tablets for oral administration and tablets for vaginal use.

The said esters of this invention are soluble in the commonly-used solvents for injection, such as camelia oil of tablets for oral administration using lactose, precipitated calcium carbonate, starch, etc. as dilution mediums. These esters may also be locally applied as vaginal tablets, in which case the dilution medium will preferably be one that can disperse the tablet soon after it is inse1ted in the vagina; for instance (1) one that can chemically form by reaction with the water content of mucus in the vagina and disperse the tablet in a comparatively short time; (2) water-soluble solids, like polyethylene glycol; .(3) oils and fats that can swiftly melt at body temperature; (4) one that is not soluble in water but can absorb water, thereby swelling and dispersing in the vagina.

Process of preparation for clinical application is illustrated in the following:

(1) Injection in 'oil for parenteral use: One gram of 1,3,5(l0)-estratriene-3,16(a),l7(,8)triol tripropionate is dissolved in ml. of camelia oil. After filtration the solution is filled into 1 ml. arnpouls being sealed and sterilized at C. for one hour.

(2) Tablets for oral administration: Ten grams of 1,3,5( 10) estratriene 3,16(a),17(fl) triol triacetate is mixed with well-dried lactose 80 g. and starch 7 g.

Using a paste prepared from 3 g. of starch and water as the binder, the granules of this mixture are prepared and by the common method into tablets each 0.1 g. in weight.

(3) Tablets for vaginal use: Five grams of 1,3,5(10) estratriene-3,16(a),17(fi)-triol tripropionate, 57.6 g. of tartaric acid, g. of lactose, and 14.7 g. of starch are mixed well and made into granules by the common method. These granules are dried overnight at 60 C. and then mixed evenly with 61.7 g. of sodium bicarbonate. The obtained substance is pressed into tablets each 0.3 g. in weight.

What is claimed is:

1. A pharmaceutical composition applicable in the treatment of vaginitis, cervicitis, menorrhagia, climacteric disturbance, and for induction of labour and shortening of labour stadium, comprising 1,3,5 (10)-estratriene-3,16(a), 17(,B)-triol tripropionate and pharmaceutical dilution mediums, the components of said compositions being in pharmaceutically acceptable amounts.

2. 1,3,5 (10) estratriene-3,16(a),17(B)-triol tripropionate.

References Cited by the Examiner UNITED STATES PATENTS 2,945,048 -7/60 Huffman 260-3975 OTHER REFERENCES Norman et al.: J.A.C.S. 78, pp. 1152-61 (1956).

LEWIS GOTTS, Primary Examiner. 

1. A PHARMACEUTICAL COMPOSITION APPLICABLE IN THE TREATMENT OF VAGINITIS, CERVICITIS, MENORRHAGIA, CLIMACTERIC DISTURBANCE, AND FOR INDUCTION OF LABOUR AND SHORTENING OF LABOUR STADIUM,COMPRISING 1,3,5(10)-ESTRATRIENE-3,16(A), 17(B)-TRIOL TRIPROPIONATE AND PHARMACEUTICAL DILUTION MEDIUMS, THE COMPONENTS OF SAID COMPOSITIONS BEING IN PHARMACEUTICALLY ACCEPTABLE AMOUNTS. 